Angiotensin receptor blocker and N-acetyl cysteine for reduction of proteinuria in patients with type 2 diabetes mellitus

Proteinuria and albuminuria are established risk factors for progressive renal damage. Albuminuria can be effectively controlled by antihypertensive drugs that interrupt the renin-angiotensin-aldosterone system. However, the efficiency of N-acetyl cysteine (NAC) in preventing diabetic nephropathy is uncertain. Renoprotective effects of angiotensin receptor blockers and NAC in preventing or reducing of proteinuria in patients with diabetic nephropathy was studied. In a randomized controlled trial, 70 patients with type 2 diabetic nephropathy (proteinuria and renal insufficiency) were studied. The patients were randomly divided into two groups and were treated with losartan, 25 mg, twice per day, with and without NAC, 600 mg twice daily (study and control groups, respectively; 35 patients in each group). Urine protein was checked before treatment and after 2 months of treatment. The two groups were comparable regarding gender, age, serum creatinine, and urine protein excretion levels. Proteinuria improved in both groups. The mean proteinuria level decreased more in patients with losartan and NAC; however, comparison of proteinuria between the two groups showed no significant difference after 2 months. Angiotensin receptor blockers reduced proteinuria due to diabetic nephropathy, and this study failed to detect additional effect when NAC was combined with these medications.